A gas turbine engine typically includes a fan section, a compressor section, a combustor section and a turbine section. Air entering the compressor section is compressed and delivered into the combustion section where it is mixed with fuel and ignited to generate a high-energy exhaust gas flow. The high-energy exhaust gas flow expands through the turbine section to drive the compressor and the fan section. The compressor section typically includes low and high pressure compressors, and the turbine section includes low and high pressure turbines.
A speed reduction device such as an epicyclical gear assembly may be utilized to drive the fan section such that the fan section may rotate at a speed different than the turbine section so as to increase the overall propulsive efficiency of the engine. In such engine architectures, a shaft driven by one of the turbine sections provides an input to the epicyclical gear assembly that drives the fan section at a reduced speed such that both the turbine section and the fan section can rotate at closer to optimal speeds.
The epicyclical gear assembly includes bearings that support rotation of gears. Loads incurred during operation can disrupt a desired relative alignment between gears and therefore the gear assembly may be supported on structures designed to accommodate such loads. However, the bearings themselves may not accommodate such loads and contribute to misalignment of meshing gears.
Although geared architectures improve propulsive efficiency, they present different challenges that can reduce any efficiency gains. Accordingly, turbine engine manufacturers continue to seek further improvements to engine performance including improvements to thermal, transfer and propulsive efficiencies.